Carton closing mechanism



Au yzl, 1962 Filed Feb. 17, 1961 R. K. GALLOWAY CARTON CLOSING MECHANISM6 Sheets-Sheet l INVENTOR ROBERT K. GALLOWAY ATTORNEY Aug. 21, 1962 R.K. GALLOWAY CARTON CLOSING MECHANISM 6 Sheets-Sheet 2 Filed Feb. 17,1961 INVENTOR ROBERT KQGALLOWAY ATTORNEY 3 N M=LHI Aug. 21, 1 62 R. K.GALLOWAY CARTON CLOSING MECHANISM 6 SheetsSheet 5 Filed Feb. 17, 1961INVENTOR ROBERT K. GALLOWAY BY X79444 ATTORNEY g- 21, 1952 R. K. GALLCJWAY 3,049,847

CARTON CLOSING MECHANISM Filed Feb. 17, 1961 6 Sheets-Sheet 4 INVENTORROBERT K. GALLOWAY ATTORNEY Afrywwhlbx.

g- 21, 1952 R. K. GALLOWAY 3,049,847

CARTON CLOSING MECHANISM Filed Feb. 17, 1961 6 Sheets-Sheet 5 :E'IE 1l FI|: 12 6 mvEN'i'oR ROBERT x. GALLOWAY ATTORNEY United States PatentOfifice 3,049,847. Patented Aug. 21, 1962 3,049,847 CARTDN CLOSINGMECHANISM Robert K. Galloway, Hoopeston, Ill., assignor to FMCCorporation, a corporation of Delaware Filed Feb. 17, 1961, Ser. No.89,982 8 Claims. (Cl. 53-374) This invention pertains to packagingmachinery, and more particularly relates to a machine for closingcartons characterized by having one or more locking tabs on one closureflap adapted to be inserted into a corresponding number of slots in acompanion flap.

In my prior, copending application, Serial No. 757,596, filed August 27,1958, and entitled Carton Closing Mechanism, I disclosed a machine forfolding the flaps at an end of a carton into carton closing relation andfor inserting locking tabs on one of the flaps into slits centrallylocated on the other flap.

Although cartons of the type handled by the closing machine of the saidcopending application have been used successfully, they have been foundto possess certain undesirable characteristics. For example, theirclosed and interengaged end flaps have the tendency to spring outwardand thus to impart a bowed, rather than the desirable flat configurationto the closed carton end. The outward displacement of the flaps not onlycauses slippage of the tabs within the locking slits and consequentweakening of the locking relationship, but materially reduces theresistance of the carton to crushing when several cartons are stackedone on top of the other. Further, the medial position of the lockingslits interferes with desirable printing of the carton end.

In order to overcome the several disadvantages enumerated above, theimproved carton illustrated in FIGS. and 6 of this application has beendeveloped. In this type of carton the outer end closure flap extendsclear across the underlying, or inner, flap so that locking tabsconstituting prolongations of the distal edge of the outer flap engagewithin slits at the crease line between the inner flap and itsassociated side panel of the carton. In other words, the lockingengagement of the outer flap with the body of the carton occurs at theproximal edge of the inner flap, rather than at the center thereof asheretofore.

The carton closing mechanism of the present invention is specificallydesigned for closing the above described, improved cartons.

It is, therefore, an object of the present invention to provide animproved carton closing mechanism.

Another object of the invention is to provide a mechanism for closingsaid improved cartons at high speed.

Another object of the present invention is to provide a mechanism forclosing said improved cartons moving therethrough at high speed, whichmechanism does not have moving parts.

These and other objects and advantages of the present invention willbecome apparent from the following description and the accompanyingdrawings, wherein:

FIG. 1 is a fragmentary perspective of the carton closing mechanism ofthe present invention.

FIGS. 2A and 2B together are a side elevation of a carton closing plowincluded in the mechanism of FIG. 1, certain parts being broken away toreveal details of structure therebehind.

FIG. 3 is an enlarged isometric of a heated crimping shoe for effectingthe final closure and setting of the end flaps of the carton.

FIG. 4 is a transverse section through the crimping shoe taken on line44 of FIG. 3.

FIG. 5 is an isometric of one of the Edge-c cartons adapted to be closedby the mechanism of the present invention, the carton being viewed frombelow and shown with its end flaps opened.

FIG. 6 is a view similar to FIG. 5 with the carton end flaps shownpartially closed.

FIGS. 7, 8, 9, 1O, 11, and 12 are sections taken on lines 7-7, 88,9"--9, 1tll0, 1111 and 12-42, respectively, of FIGS. 2A and 2B andillustrating successive steps of closing and looking the carton endflaps.

One of the cartons C adapted to be closed by the mechanism of thepresent invention is illustrated in FIGS. 5 and 6, and comprises a toppanel 26, a bottom panel 22, and forward and rear panels 24- and 26,respectively. End flaps 28, 30, 32 and 34- are connected to the lateraledges of the panels 29, 22, 24 and 26 along crease lines 29, 31, 33 and35-, respectively. A plurality of spaced locking tabs 36 are connectedto the distal end of the flap 28 associated with the top panel 20 andconstitute prolongations thereof. A plurality of arcuate slits 38 areformed partially in the bottom panel 22 and partially in the flap 3%associated therewith. It will be noted that the end portions of thearcuate slits 38 are in the bottom panel 22 and that the centralportions of the slits are in the end flap 30. When the flap 30 is foldedto its closed position, the central portion of each slit 38 forms a lip39 which extends outward beyond the outer surface of the flap 39.

The carton closing mechanism 40 (FIG. 1) of the present inventioncomprises 'a conveyor 42 for successively advancing the cartons C to beclosed between two closing plows or shoes 44 and 46 which fold the topand bottom carton flaps 28 and 30 into overlapping relation with eachother, and insert the tabs 36 on the top flap 28 into the slits 38 in aprogressive, zipper-like fashion as the cartons move therebetween.

Since the two plows 44 and 46 are mirror images of each other, only theplow 44 will be described in detail.

The plow 44 comprises a C-shaped bracket 50 (FIGS. 1, 2A, 2B, 7, 8, 9,and 10) secured to a mounting bedplate 52 (FIG. 213) by bolts 54. Twovertically spaced support plates 56 and 58 (FIGS. 2A, 2B, 7, 8, '9, 10,11, and 12) are fastened to the opposed edges of the C-shaped bracket 50by a plurality of cap screws 60' and 62, respectively. An upper cartonguide plate 64 is fixed to the under surface of the upper support plate56 and, similarly, a lower guide plate 66 is fixed to the upper surfaceof the lower support plate 58. The rear, or carton-receiving, end 68 ofthe upper guide plate 64 slopes upward and rearward so that upper endflap 28 of each carton advancing therep-ast will be guided thereunder.Similarly the rear, or carton receiving end, 70 of the lower guide plate66 inclines downward and rearward so that the lower end flap 30 of thecarton will be guided thereabove.

A spacer block 72 (FIGS. 2B and 7) is fixed to the web portion 74 of theC-shaped member 50 adjacent the rear, or entrance, end thereof by aplurality of cap screws 76 which extend through vertical slots 78 in theweb portion. The block 72 extends inward from the web portion andsupports a vertical plate 80 fastened to its inner end by countersunkset screws 81 which project through openings in the plate 84 and arethreaded into suitable openings provided in the inner surface of theblock 72. The plate 80 serves to retain the forward and rear end flaps32 and 34 of the carton in their folded relation previously establishedby a mechanism not illustrated herein. The flaps 32 and 34 ride againstthe inner surface of the plate 80. The upper and lower edges of theplate 80 are chamfered as illustrated in FIG. 213 at 82 and 84, respectively to provide relatively thin edges about which the upper and lowercarton flaps 28 and 30 are folded.

A guide and support bar is mounted in a recess in the upper surface ofthe block 72 so that its upper surface is coplanar with the uppersurface of the block. The bar 90' projects forward and upward therefromto contact and support the upper carton flap 23 briefiy after a carton Chas moved past the block '72, with the outer edge of the guide bar 90just inside the line of juncture between the locking tabs 36 and theflap 23. A depending cam 92 is fixed to the inner surface of the upperleg 94 of the C-shaped bracket 50 by a cap screw 96. The cam 92 dependspast the outer edge of the bar 96 in position to be contacted by thetabs 36 as they pass beyond the upper guide plate 68 and, while the flap28 is supported by the bar 90, to fold the tabs downward to a positionsubstantially perpendicular to the flap 28, as shown in FIG. 7.

Just forward of the cam plate 92, the lower edge of the previouslydescribed vertical plate 86 is provided with a downwardly projecting camedge 161} (P16. 213), and the lower guide plate 66 is cut out asindicated at 101 (-FIG. 1) adjacent thereto. As a carton C movestherepast, the cam edge 100 presses downward on the crease line 31between the lower carton panel 22 and the lower flap 30 and causes theslits 38 to pop open.

Forward of the cam edge 100, the bottom guide plate 66 is provided withan integral wing cam 110 (FIGS. 2A, 2B and 8) which projects outwardtherefrom and gradually turns upward until its forward end issubstantially perpendicular to the guide plate 66. As each cartonadvances, the wing cam folds the bottom end flap 36 thereof around thelower thin edge of the plate 80. A finger 112 (FIGS. 2A and 9) projectsforward from the forward edge of the Wing earn 116 to retain the bottomflap 3% ver tical and closely adjacent the outer face of the plate 86until the top flap 28 is folded downward thereover.

Adjacent the forward end of the Wing earn 110, the upper guide plate 64is provided with an outwardly projecting wing cam 120 (FIGS. 2A, 8, 9and which gradually turns downward until it becomes substantiallyperpendicular to the guide plate 64. Its function is to fold the top endflap 28 downward around the upper thin edge of the plate 80 and intooverlying relation with the bottom end flap 30.

A block 122 (FIGS. 2A and 8) is fastened to the lower flange of theC-shaped bracket 50 adjacent the forward end of the wing cam 110 by aplurality of bolts 124. A guide rod 126 is clamped to the block 122 andprojects forward, downward and inward therefrom in the manner bestillustrated in FIGS. 8 and 9 so that its inner surface is contacted byand guides the tabs 36 as shown in FIG. 9 as the upper flap 23 is turneddownward by the cam wing 120. A second guide rod 123 (FIGS. 2A and 8) isfixed to the upper surface of the rod 126 and extends diagonally upwardand rearward therefrom to prevent any of the tabs 36 from passing aboveand thus failing to engage the rod 126. As best seen in FIG. 9, thelower inner surface of the rod 126 is chamfered adjacent the rodsforward end so that the lip 39 of the slit 33 will pass therebeneathwhile the tab 36 riding on the guide bar 126 will be guided above thelip 39 and into the slit 38.

Adjacent the forward end of the guide bar 126, a relatively thin plate130' (FIGS. 2A and 10) is fixed to the upper surface of the supportplate 58. The inner edge of the plate 130 is bent upward and then inwardas best seen in FIG. 11 to provide an inwardly projecting ledge 132beneath which the lip 39 projecting from the carton C adjacent each ofthe slits 38 rides. The tab 36 is guided by the bar 126 above the lip132 to enter the slit 38. The rearmost end 134 (FIGS. 2A and 10) of thelip 132 slopes upward and rearward to ensure that the projecting lip 39on the carton will be guided thereunder.

A presser bar 140 (FIGS. 2A, 10 and 11) is adjustably mounted on theupper surface of the plate 131) by capserews 142 which project throughsuitable slots formed in the bar 140 and are threaded into tappedopenings in the lower support plate 58. The bar 140 is inclinedrelatively to the line of travel of the carton C so that its forwardmostend is closer to said line of travel than is its rearrnost end. It willbe seen from a comparison of d FEGS. l0 and 11 that the distal edge ofthe flap 28 will contact the inner surface of the bar 146 and will bepressed inward thereby so that the tabs 36 will slide along the uppersurface of the lip 132 and partially enter the slits 38 in the mannerillustrated in FIG, 11.

The final positioning of the tabs 36 within the slits 38 is accomplishedby the crimping shoe assembly 150 (FIGS. 2A, 3, 4, and 12). The crimpingshoe assembly 150 comprises a C-shaped block 152 mounted between thesupport plates 56 and 58 with its open end facing inward. The upper andlower flanges 154 and 156 of the block 152 form continuations of theupper and lower guide plates 64 and 66, respectively. The rear portion160 of the inwardly facing surface of the web portion of the block 152is inclined rearward and outward to guide the carton end into thecrimping shoe from the forward end of the presser bar 149.

The upper surface of the lower flange 156 is recessed as indicated at162, and a slot 164 is cut into the web portion of the block 152 toaccommodate a pivotally mounted presser lever 166. The lever 166 ispivotally mounted at 168 on a vertical pivot pin (not shown), and aspring 17%), mounted in a lateral blind bore "172 in the block 152,presses against the forward end of the lever 166 to urge the sameinward. A heater assembly 174 is fixed to the outer surface of the block152 so as to transmit heat to the latter. The heating of the crimpingshoe not only facilitates the passage of the carton therethrough bymaterially reducing the frictional drag, but also the heat aids insetting the carton in its locked condition.

As a carton C leaves the presser bar 140, the inclined portion 160 ofthe block 152 guides the end of the carton into the crimping shoe 150.The carton pushes the lever 166 into the slot 164 against the pressureof the spring 170. The spring pressure causes the lever 166 to push theflap 28 tightly against the flap 3t and successively forces the tabs 36all the way into the slits 38 to their final locked position.

Thus it may be seen that as a carton advances with its end slidablyengaged with the closing plow, the lower end flap 31) is folded upwardin an action that progresses smoothly from one lateral edge to theother, and the upper end flap 28 is folded downward into overlyingrelation therewith in a similar smooth progressive action, and, as thisoccurs, the locking tabs 36 are successively entered into theirrespective slits 38. As the carton progresses past the presser lever166, the tabs 36 are successively inserted fully into the slits 38. Eachtab enters and seats within its slit 38 in a twisting motion, theleading edge entering first, after which the tab experiences a sort oftwisting, a rotary movement in its own plane, causing the subsequententry of the trailing edge and thereafter full insertion of the tab intothe slit.

Two crimping members and 182 are fixed to the terminal end of the block152. The upper member 180 is fixed by capscrew 184 and forms a rigidcontinuation of the upper flange 154. It is a back up, or thrustresisting member. The lower member 182 is pivotally mounted on acapscrew 186, and is provided with an upwardly projecting grooving ridge188 in position to engage the bottom carton panel 22 just inside of thecrease line 31 thereof. A spring 19% mounted between the outer ends ofthe members 180 and 182 yieldably retains the pivoted crimping member inposition for its ridge 188 to press upward against the bottom panel withsufficient force to bind the panel upward immediately adjacent the foldline 31 and thus sharply crimp the material of the carton along the foldline in a manner that minimizes or eliminates any tendency for thebottom flap to spring back away from its fully closed position. Thiscrimping also causes the inner surface of the bottom panel 22 to hearmore tightly against the lower faces of the tabs 36 and thus add to thesecurity with which the tabs are retained within the slits 38.

Since after closure of the carton end is completed, the

distal edge of the bottom flap 30 engages the inner surface of thefolded down top fiap 28 immediately adjacent the hinge line 29 of thelatter, and since the fold line 31 of the bottom flap 39 is sharplycrimped as above explained, the bottom flap is securely retained in itsclosed position, and in a substantially flat condition.

Likewise with the carton end closed, the distal edge of the overlying,top flap 28 is attached by its tabs 36 directly to a part of the cartonthat does not yield longitudinally, i.e., to the lower panel 22 and theregion of the underlying, bottom flap 30 immediately adjacent its hingeline 31. Therefore, tendency for the end flaps 28 and 3t) to springback, away from their fully closed position is practically, if notcompletely, eliminated, with the result that the end of the closedcarton remains flat rather than becoming outwardly bowed as in the caseif cartons having closure flaps that interlock midway between the hingelines along which they are connected to their respective top and bottompanels of the carton.

While a preferred embodiment of the present invention is describedherein, it should be noted that various changes may be made thereinwithout departing from the spirit of the invention as defined in theappended claims.

The invention having thus been described, what is claimed and desired tobe protected by Letters Patent is:

1. in a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for advancing an erected carton along apredetermined path with the carton disposed transversely of theconveyor, carton closing means disposed adjacent said path includingmeans mounted in position for engagement by the tab of the advancingcarton for folding said tab downward to a position substantiallyperpendicular to said upper fiap, a lower cam plate having an upturnedwing in position for engagement by said lower flap for folding the sameupward to a position substantially normal to said lower panel, an uppercam having a downwardly turned wing at a point forward of said upwardlyturned Wing on the lower cam plate and in position for engagement bysaid upper flap for folding the same downward toward a positionoverlying the upwardly turned lower flap, means adjacent said downwardlyturned wing of the upper cam and cooperating therewith to guide said tabinto said slit as said upper flap is folded downward, and cam means forengaging the outer surface of said upper flap adjacent the distal endthereof and forcing the same inward to push said tab into said slit.

2. in a carton closing mechanism for closing .a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for advancing an erected carton along apredetermined path with the carton disposed transversely of theconveyor, carton closing means disposed adjacent said path includingmeans mounted in position for engagement by the tab of the advancingcarton for folding said tab downward to a position substantiallyperpendicular to said upper flap, means slidably engagin the undersurface of said upper flap to support the same while said tab is beingfolded down by said tab folding means, a lower cam plate having anupturned wing in position for en gagement by said lower flap for foldingthe same upward to a position substantiaily normal to said lower panel,an upper cam having a downwardly turned wing at a 6. point forward ofsaid upwardly turned wing on the lower cam plate and in position forengagement by said upper flap for folding the same downward toward aposition overlying the upwardly turned lower flap, means adjacent saiddownwardly turned wing of the upper cam and cooperating therewith toguide said tab into said slit as said upper flap is folded downward, andcam means for engaging the outer surface of said upper flap adjacent thedistal end thereof and forcing the same inward to push said tab intosaid slit.

3. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for advancing an erected carton along apredetermined path with the carton disposed transversely of theconveyor, carton closing means disposed adjacent said path includingmeans mounted in position for engagement by the tab of the advancingcarton for folding said tab downward to a position substantiallyperpendicular to said upper flap, means engageable by the advancingcarton for pressing downward substantially on the crease line betweensaid lower flap and the lower panel to open said slit, a lower cam platehaving an upturned wing in position for engagement by said lower flapfor folding the same upward to a position substantially normal to saidlower panel, an upper cam having a downwardly turned wing at a pointforward of said upwardly turned wing on the lower cam plate and inposition for engage ment by said upper flap for folding the samedownward toward a position overlying the upwardly turned lower flap,means adjacent said downwardly turned wing of the upper cam andcooperating therewith to guide said tab into said opened slit as saidupper flap is folded downward, and cam means for engaging the outersurface of said upper flap adjacent the distal end thereof and forcingthe same inward to push said tab into said slit.

4. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for an erected carton along a predetermined pathwith the carton disposed transversely of the conveyor, carton closingmeans disposed adjacent said path including an elongate plate havingchamfered upper and lower creasing edges adjacent and parallel to saidpath, means mounted in position for engagement by the tab of theadvancing carton for folding said tab downward to a positionsubstantially perpendicular to said upper flap, a lower cam plate havingan upturned wing in position for engagement by said lower flap forfolding the same upward around said lower creasing edge to a positionsubstantially normal to said lower panel, an upper cam having adownwardly turned wing at a point forward of said upwardly turned wingon the lower cam plate and in position for engagement by said upper flapfor folding the same downward around said upper creasing edge toward aposition overlying the upwardly turned lower flap, means adjacent saiddownwardly turned wing of the upper cam and cooperating therewith toguide said tab into said slit as said upper flap is folded downward, andcam means for engaging the outer surface of said upper flap adjacent thedistal end thereof and forcing the same inward to push said tab intosaid slit.

5. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for advancing an erected carton along apredetermined path with the carton disposed transversely of theconveyor, carton closing means disposed adjacent said path including aplate having chamfered upper and lower creasing edges extendingalongside said path, means mounted in position for engagement by the tabof the advancing carton for folding said tab downward to a positionsubstantially perpendicular to said upper flap, depending cam means onsaid plate for pressing downward substantially on the crease linebetween said lower panel and said flap thereon to open said slit, alower cam plate having an upturned wing in position for engagement bysaid lower flap for folding the same upward around said lower creasingedge to a position substantially normal to said lower panel, an uppercam having a downwardly turned wing at a point forward of said upwardlyturned wing on the lower cam plate and in position for engagement bysaid upper flap for folding the same downward around said upper creasingedge toward a position overlying the upwardly turned lower flap, meansadjacent said downwardly turned wing of the upper cam and cooperatingtherewith to guide said tab into said opened slit as said upper flap isfolded downward, and cam means for engaging the outer surface of saidupper flap adjacent the distal end thereof and forcing the same inwardto push said tab into said slit.

. 6. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein substantially on the crease line between the lower flap and thelower panel, the upper closure flap having a tab projecting from itsdistal edge in position to enter the slit, the improvement whichcomprises a conveyor for advancing an erected carton along apredetermined path with the carton disposed transversely of the conveyorand with said end flaps horizontal and projecting laterally from theirrespectively associated panels, carton closing means disposed adjacentsaid pat-h including means mounted in position for engagement by the tabof the advancing carton for folding said tab downward to a positionsubstantially perpendicular to said upper flap, means slidably engagingand supporting said upper flap in a horizontal plane while said tahthereon is folded down by said tab folding means, means engageable bythe advancing carton for pressing down substantially on said crease linebetween the lower panel and the lower flap to open the slit, a lower camplate having an upturned wing in position for engagement by said lowerflap for folding the same upward to a position substantially normal tosaid lower panel, an upper cam having a downwardly turned wing at apoint forward of said upwardly turned wing on the lower cam plate and inposition for engagement by said upper flap for folding the same downwardtoward a position overlying the upwardly turned lower flap, meansadjacent said downwardly turned wing of the upper cam and cooperatingtherewith to guide said tab into said opened slit as said upper flap isfolded downward, and cam means for engaging the outer surface of saidupper flap adjacent the distal end thereof and forcing the same inwardto push said tab into said slit.

7. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein intersecting the crease line between the lower flap and thelower panel, the ends of said slit being in said lower panel and themid-portion of the slit being in said lower flap, the upper closure flaphaving a tab projecting from its distal edge in position to enter theslit, the improvement which comprises a conveyor for advancing anerected carton along a predetermined path with the carton disposedtransversely of the conveyor and with said end closure flaps projectinglaterally beyond said path, carton closing means disposed adjacent saidpath including means mounted in position for engagement by the tab ofthe advancing carton for folding said tab downward to a positionsubstantially perpendicular to said upper flap, a lower cam plate havingan upturned wing in position for engagement by said lower flap forfolding the same upward to a position substantially normal to said lowerpanel, the part of said lower panel defined by said mid-portion of thearcuate slit remaining horizontal while said lower flap is folded upwardto present a lip projecting beyond the outer face of the upwardly turnedlower flap, an upper cam having a downwardly turned wing at a pointforward of said upwardly turned wing on the lower cam plate and inposition for engagement by said upper flap for folding the same downwardtoward a position overlying the upwardly turned lower flap, lip engagingmeans mounted in position for said projecting lip to pass thereunderafter the lower flap has folded upward, means adjacent said downwardlyturned wing of the upper cam and cooperating therewith to guide said tabover said lip engaging means and into said slit as said upper flap isfolded downward, and cam means for engaging the outer surface of saidupper flap adjacent the distal end thereof and forcing the same inwardto push said tab into said slit.

8. In a carton closing mechanism for closing a carton including lowerand upper end closure flaps hingedly connected to the lower and upperpanels respectively of the carton, said carton having an arcuate slittherein intersecting the crease line between the lower flap and thelower panel with the ends of the slit in the lower panel of themid-portion of the slit in the lower flap, the upper closure flap havinga tab projecting from its distal edge in position to enter the slit, theimprovement which comprises a conveyor for advancing an erected cartonalong a predetermined path with the carton disposed transversely of theconveyor, carton closing means disposed adjacent said path including anelongate plate extending alongside said path, means mounted in positionfor engagement by the tab of the advancing carton for folding said tabdownward to a position substantially perpendicular to said upper flap,means slidably supporting said upper flap while said tab thereon isbeing folded, cam means on said elongate plate for depressing said lowerpanel adjacent said fold line thereof to open said slit, 2. lower camplate having an upturned wing in position for engagement by said lowerflap for folding the same upward around the lower edge of said elongateplate and to a position substantially normal to said lower panel, anupper cam having a downwardly turned wing at a point forward of saidupwardly turned wing on the lower cam plate and in position forengagement by said upper flap for folding the same downward around theupper edge of said elongate plate and toward a position overlying theupwardly turned lower flap, means adjacent said downwardly turned wingof the upper cam and cooperating therewith to guide said tab into saidopen slit as said upper flap is folded downward, and cam means forengaging the outer surface of said upper flap adjacent the distal endthereof and forcing the same inward to push said tab into said slit.

Harkess Jan. 4, 1955 Galloway Apr. 18, 1961

